Method for making magnetic components with M-phase coupling, and related inductor structures

Abstract

An M-phase coupled inductor including a magnetic core and M windings, where M is an integer greater than one. The magnetic core is formed of a core material, and the magnetic core includes a first outer leg forming a first gap. The first gap includes a first gap material having lower magnetic permeability than the core material. Each winding is wound at least partially around at least a portion of the magnetic core, and each winding has a respective leakage inductance. The first gap causes the leakage inductances to be greater than if the first outer leg did not form the first gap. The coupled inductor may be used in a power supply, and the power supply may be used in a computing apparatus.

1. An M-phase coupled inductor, M being an integer greater than one, the coupled inductor comprising:
 a magnetic core formed of core material, the magnetic core including:
 first and second opposing end magnetic elements, 
 M adjacent inner legs, each of the M adjacent inner legs disposed between and connecting the first and second opposing end magnetic elements, and 
 a first outer leg:
 connected to the first opposing end magnetic element at a first end thereof outside of the M adjacent inner legs, 
 connected to an innermost edge of the first opposing end magnetic element nearest an innermost edge of the second opposing end magnetic element, and extending along a first lengthwise direction toward a first end of the second opposing end magnetic element outside of the M adjacent inner legs, and 
 including a first gap along the first lengthwise direction, the first gap having a thickness less than a distance between the respective innermost edges of the first and second opposing end magnetic elements at their respective first ends, the first gap including first gap material having lower magnetic permeability than the core material; and 
 
 
 M windings, each winding wound at least partially around at least a portion of a respective one of the inner legs, each winding having a respective leakage inductance, 
 wherein the first gap provides a path for leakage flux, the leakage flux contributing to the respective leakage inductances of the M windings, and 
 wherein each inner leg has a respective width, and adjacent inner legs are separated by a separation distance that is less than 25% of the respective width of either adjacent inner leg. 
 
     
     
       2. The coupled inductor of  claim 1 , M being an integer greater than two. 
     
     
       3. The coupled inductor of  claim 2 , the magnetic core further including a second outer leg:
 connected to the first opposing end magnetic element at a second end thereof outside of the M adjacent inner legs, the second end of the first opposing end magnetic element being different from the first end of the first opposing end magnetic element, 
 connected to the innermost edge of the first opposing end magnetic element, and extending along a second lengthwise direction toward a second end of the second opposing end magnetic element outside of the M adjacent inner legs, the second end of the second opposing end magnetic element being different from the first end of the second opposing end magnetic element, and 
 including a second gap along the second lengthwise direction, the second gap having a thickness less than a distance between the respective innermost edges of the first and second opposing end magnetic elements at their respective second ends, 
 the second gap including second gap material having lower magnetic permeability than the core material, the M adjacent inner legs being disposed between the first and second outer legs, the second gap providing an additional path for leakage flux. 
 
     
     
       4. The coupled inductor of  claim 3 , adjacent inner legs being separated by a separation distance that is less than 10% of the respective width of either adjacent inner leg. 
     
     
       5. The coupled inductor of  claim 3 , each winding being a single layer and single turn winding having substantially rectangular cross section. 
     
     
       6. The coupled inductor of  claim 3 , the second gap material being different than the first gap material. 
     
     
       7. The coupled inductor of  claim 3 , the second gap material being the same as the first gap material. 
     
     
       8. The coupled inductor of  claim 3 , at least one of the gap materials including a non-magnetic material selected from the group consisting of air, insulating tape, plastic, glue, and paper. 
     
     
       9. The coupled inductor of  claim 1 , the magnetic core further including a second outer leg:
 connected to the first opposing end magnetic element at a second end thereof outside of the M adjacent inner legs, the second end of the first opposing end magnetic element being different from the first end of the first opposing end magnetic element, 
 connected to the innermost edge of the first opposing end magnetic clement, and extending along a second lengthwise direction toward a second end of the second opposing end magnetic element outside of the M adjacent inner legs, the second end of the second opposing end magnetic element being different from the first end of the second opposing end magnetic element, and 
 including a second gap along the second lengthwise direction, the second gap having a thickness less than a distance between the respective innermost edges of the first and second opposing end magnetic elements at their respective second ends, 
 the second gap including second gap material having a lower magnetic permeability than the core material, the M adjacent inner legs being disposed between the first and second outer legs, the second gap providing an additional path for leakage flux. 
 
     
     
       10. The coupled inductor of  claim 9 , the first lengthwise direction being parallel to the second lengthwise direction. 
     
     
       11. An M-phase power supply, M being an integer greater than one, the power supply comprising:
 a coupled inductor including:
 a magnetic core formed of core material, the magnetic core including:
 first and second opposing end magnetic elements, 
 M adjacent inner legs, each of the M adjacent inner legs disposed between and connecting the first and second opposing end magnetic elements, and 
 a first outer leg:
 connected to the first opposing end magnetic element at a first end thereof outside of the M adjacent inner legs, 
 connected to an innermost edge of the first opposing end magnetic element nearest an innermost edge of the second opposing end magnetic element, and extending along a first lengthwise direction toward a first end of the second opposing end magnetic element outside of the M adjacent inner legs, and 
 including a first gap along the first lengthwise direction, the first gap having a thickness less than a distance between the respective innermost edges of the first and second opposing end magnetic elements at their respective first ends, the first gap including first gap material having lower magnetic permeability than the core material, and 
 
 
 M windings, each winding wound at least partially around at least a portion of a respective one of the inner legs, each winding having a respective first end, a respective second end, and a respective leakage inductance, each first end electrically coupled to a common first node, 
 wherein the first gap provides a path for leakage flux, the leakage flux contributing to the respective leakage inductances of the M windings; and 
 
 M switching circuits, each switching circuit electrically coupled to the second end of a respective winding and configured and arranged to switch the second end between at least two different voltages. 
 
     
     
       12. The power supply of  claim 11 , M being an integer greater than two. 
     
     
       13. The power supply of  claim 12 , the magnetic core further including a second outer leg:
 connected to the first opposing end magnetic element at a second end thereof outside of the M adjacent inner legs, the second end of the first opposing end magnetic element being different from the first end of the first opposing end magnetic element, 
 connected to the innermost edge of the first opposing end magnetic element, and extending along a second lengthwise direction toward a second end of the second opposing end magnetic element outside of the M adjacent inner legs, the second end of the second opposing end magnetic element being different from the first end of the second opposing end magnetic element, and 
 including a second gap along the second lengthwise direction, the second gap having a thickness less than a distance between the respective innermost edges of the first and second opposing end magnetic elements at their respective second ends, 
 the second gap including second gap material having lower magnetic permeability than the core material, at least one of the gap materials including a non-magnetic material selected from the group consisting of air, insulating tape, plastic, glue, and paper, the second gap providing an additional path for leakage flux. 
 
     
     
       14. The power supply of  claim 13 , each inner leg having a respective width, adjacent inner legs being separated by a separation distance that is less than 25% of the respective width of either adjacent inner leg. 
     
     
       15. The power supply of  claim 14 , each winding being a single layer and single turn winding having substantially rectangular cross section. 
     
     
       16. The power supply of  claim 13 , each first end extending from a first side of the coupled inductor, and each second end extending from a second side of the coupled inductor. 
     
     
       17. The power supply of  claim 13 , at least two first ends extending from different respective sides of the coupled inductor. 
     
     
       18. The power supply of  claim 13 , at least two second ends extending from different respective sides of the coupled inductor. 
     
     
       19. The power supply of  claim 13 , each winding being a single layer and single turn winding having substantially rectangular cross section. 
     
     
       20. The power supply of  claim 19 , each switching circuit comprising:
 at least one switching device; 
 a transformer including a primary winding and a secondary winding, the primary winding electrically coupled to the at least one switching device; and 
 a rectification circuit electrically coupled between the secondary winding and the second end of the respective winding of the switching circuit. 
 
     
     
       21. The power supply of  claim 20 , the rectification circuit including at least one switching device. 
     
     
       22. The power supply of  claim 19 , the first node being an input voltage node. 
     
     
       23. The power supply of  claim 19 , the first node being an output voltage node. 
     
     
       24. The power supply of  claim 19 , the first node being a ground node. 
     
     
       25. A computing apparatus, comprising:
 a computer processor; and 
 an M-phase power supply electrically coupled to the processor for at least partially powering the processor, M being an integer greater than one, the power supply including:
 a coupled inductor including:
 a magnetic core formed of core material, the magnetic core including:
 first and second opposing end magnetic elements, 
 M adjacent inner legs, each of the M adjacent inner legs disposed between and connecting the first and second opposing end magnetic elements, and 
 a first outer leg: 
  connected to the first opposing end magnetic element at a first end thereof outside of the M adjacent inner legs, 
  connected to an innermost edge of the first opposing end magnetic element nearest an innermost edge of the second opposing end magnetic element, and extending along a first lengthwise direction toward a first end of the second opposing end magnetic element outside of the M adjacent inner legs, and 
  including a first gap along the first lengthwise direction, the first gap having a thickness less than a distance between the respective innermost edges of the first and second opposing end magnetic elements at their respective first ends, the first gap including first gap material having lower magnetic permeability than the core material; and 
 
 M windings, each winding wound at least partially around at least a portion of a respective one of the inner legs, each winding having a respective first end, a respective second end, and a respective leakage inductance, each first end electrically coupled to a common first node, and 
 wherein the first gap provides a path for leakage flux, the leakage flux contributing to the respective leakage inductances of the M windings; and 
 
 M switching circuits, each switching circuit electrically coupled to the second end of a respective winding and configured and arranged to switch the second end between at least two different voltages. 
 
 
     
     
       26. The computing apparatus of  claim 25 , M being an integer greater than two. 
     
     
       27. The computing apparatus of  claim 26 , the magnetic core further including a second outer leg:
 connected to the first opposing end magnetic element at a second end thereof outside of the M adjacent inner legs, the second end of the first opposing end magnetic element being different from the first end of the first opposing end magnetic element, 
 connected to the innermost edge of the first opposing end magnetic element, and extending along a second lengthwise direction toward a second end of the second opposing end magnetic element outside of the M adjacent inner legs, the second end of the second opposing end magnetic element being different from the first end of the second opposing end magnetic element, and 
 including a second gap along the second lengthwise direction, the second gap having a thickness less than a distance between the respective innermost edges of the first and second opposing end magnetic elements at their respective second ends, the second gap including second gap material having lower magnetic permeability than the core material, at least one of the gap materials including a non-magnetic material selected from the group consisting of air, insulating tape, plastic, glue, and paper, the second gap providing an additional path for leakage flux. 
 
     
     
       28. The computing apparatus of  claim 27 , each winding being a single layer and single turn winding having substantially rectangular cross section. 
     
     
       29. The computing apparatus of  claim 27 , each inner leg having a respective width, adjacent inner legs being separated by a separation distance that is less than 25% of the respective width of either adjacent inner leg. 
     
     
       30. The computing apparatus of  claim 29 , each winding being a single layer and single turn winding having substantially rectangular cross section. 
     
     
       31. The coupled inductor of  claim 1 , each of the M adjacent inner legs being arranged in parallel. 
     
     
       32. An M-phase coupled inductor, M being an integer greater than one, the coupled inductor comprising:
 a magnetic core formed of core material selected from the group consisting of a ferrite material and a powdered iron material, the magnetic core including:
 first and second opposing end magnetic elements, 
 M adjacent inner legs, each of the M adjacent inner legs disposed between and connecting the first and second opposing end magnetic elements, and 
 a first outer leg:
 connected to the first opposing end magnetic element at a first end thereof outside of the M adjacent inner legs, 
 connected to an innermost edge of the first opposing end magnetic element nearest an innermost edge of the second opposing end magnetic element, and extending along a first lengthwise direction toward a first end of the second opposing end magnetic element outside of the M adjacent inner legs, and 
 including a first gap along the first lengthwise direction, the first gap having a thickness less than a distance between the respective innermost edges of the first and second opposing end magnetic elements at their respective first ends, the first gap including first gap material having lower magnetic permeability than the core material; and 
 
 
 M windings, each winding wound at least partially around at least a portion of a respective one of the inner legs, each winding having a respective leakage inductance, 
 wherein the first gap provides a path for leakage flux, the leakage flux contributing to the respective leakage inductances of the M windings. 
 
     
     
       33. The coupled inductor of  claim 32 , M being an integer greater than two. 
     
     
       34. The coupled inductor of  claim 33 , the magnetic core including a second outer leg:
 connected to the first opposing end magnetic element at a second end thereof outside of the M adjacent inner legs, the second end of the first opposing end magnetic element being different from the first end of the first opposing end magnetic element, 
 connected to the innermost edge of the first opposing end magnetic element, and extending along a second lengthwise direction toward a second end of the second opposing end magnetic element outside of the M adjacent inner legs, the second end of the second opposing end magnetic element being different from the first end of the second opposing end magnetic element, and 
 including a second gap along the second lengthwise direction, the second gap having a thickness less than a distance between the respective innermost edges of the first and second opposing end magnetic elements at their respective second ends, the second gap including second gap material having lower magnetic permeability than the core material, the M adjacent inner legs being disposed between the first and second outer legs, the second gap providing an additional path for leakage flux. 
 
     
     
       35. The coupled inductor of  claim 34 , each inner leg having a respective width, adjacent inner legs being separated by a separation distance that is less than 25% of the respective width of either adjacent inner leg.